System, method and apparatus for RF power compensation in a plasma processing system

Abstract

Plasma processing systems and methods including a plasma processing chamber and an RF transmission path. The plasma processing chamber including an electrostatic chuck. The RF transmission path including one or more RF generators, a match circuit coupled the RF generator and an RF feed coupling the match circuit to the electrostatic chuck. The system also includes an RF return path coupled between the plasma processing chamber and the RF generator. A plasma processing system controller is coupled to the plasma processing chamber and the RF transmission path. The controller includes recipe logic for at least one plasma processing recipe including multiple plasma processing settings and an RF power compensation logic for adjusting at least one of the plasma processing settings.

The invention claimed is: 
     
       1. A plasma processing system comprising:
 a plasma processing chamber including an electrostatic chuck; 
 an RF transmission path including:
 at least one RF generator; 
 a match circuit having an input coupled to an output of the at least one RF generator; and 
 an RF feed coupling a match circuit output to an RF input to the electrostatic chuck; 
 an RF return path coupled between the plasma processing chamber and the at least one RF generator; and 
 a plasma processing system controller coupled to the plasma processing chamber and the RF transmission path, the system controller including:
 a recipe logic including computer readable instructions for at least one plasma processing recipe including a plurality of plasma processing settings; and 
 an RF power compensation logic including computer readable instructions for adjusting at least one of the plurality of plasma processing settings. 
 
 
 
     
     
       2. The system of  claim 1 , wherein the recipe logic includes computer readable instructions for a calibration plasma process recipe. 
     
     
       3. The system of  claim 2 , wherein the plasma processing chamber includes a sensor configured to measure at least one of a voltage, and/or a current, and/or a frequency, and/or a phase of a signal, and/or a plasma process chamber temperature, and/or a plasma process chamber pressure, and/or a flow rate input or output from the plasma process chamber, and/or a mixture of process gases input to the plasma process chamber, and/or the etch byproducts produced in the plasma process chamber. 
     
     
       4. The system of  claim 2 , wherein the plasma processing chamber includes a sensor configured to measure a plasma induced voltage on a wafer supported on the electrostatic chuck during an execution of a calibration plasma process defined by the calibration plasma process recipe. 
     
     
       5. The system of  claim 2 , wherein the RF power compensation logic further includes computer readable instructions for measuring at least one plasma parameter during an execution of a calibration plasma process. 
     
     
       6. The system of  claim 5 , wherein the RF power compensation logic further includes computer readable instructions for comparing a measured at least one plasma parameter to a corresponding at least one plasma parameter predicted by a complete RF transmission line model. 
     
     
       7. The system of  claim 6 , wherein the complete RF transmission line model includes RF models for the RF transmission path, the plasma and the RF return path. 
     
     
       8. The system of  claim 1 , wherein the at least one RF generator includes at least two RF generators and each one of the at least two RF generators generate a different output signal frequency. 
     
     
       9. The system of  claim 1 , wherein the at least one RF generator includes at least three RF generators and each one of the at least three RF generators generate a different output signal frequency. 
     
     
       10. A method for adjusting a plasma process recipe comprising:
 determining an RF compensation adjustment including:
 applying a calibration plasma process to at least one wafer in a plasma processing chamber; 
 measuring at least one plasma parameter during the calibration plasma process; and 
 comparing the measured at least one plasma parameter to a corresponding at least one plasma parameter predicted by a complete RF transmission line model to determine an RF compensation adjustment, the complete RF transmission line model including an RF transmission path, a plasma in the plasma processing chamber and an RF return path; 
 receiving the RF compensation adjustment in an RF power compensation logic; 
 adjusting at least one of a plurality of plasma processing settings included in the plasma processing recipe; 
 storing the adjusted at least one of a plurality of plasma processing settings; and 
 applying a plasma process to a process wafer, the applied plasma process including the adjusted at least one of the plurality of plasma processing settings. 
 
 
     
     
       11. The method of  claim 10 , wherein the RF power compensation logic compares the measured at least one plasma parameter to the corresponding at least one plasma parameter predicted by a complete RF transmission line model. 
     
     
       12. The method of  claim 10 , wherein the RF compensation adjustment is determined by a difference between the measured at least one plasma parameter and the corresponding at least one plasma parameter predicted by the complete RF transmission line model. 
     
     
       13. The method of  claim 10 , wherein the at least one of the plurality of plasma processing settings include at least one of an RF power, and/or an RF voltage, and/or an RF current, and/or a phase of an RF signal, and/or an RF frequency. 
     
     
       14. The method of  claim 10 , wherein the at least one of the plurality of plasma processing settings include an output of a match circuit included in the RF transmission path. 
     
     
       15. The method of  claim 10 , wherein the at least one of the plurality of plasma processing settings include a bias voltage, and/or a plasma processing chamber pressure, and/or a plasma processing chamber temperature, and/or a plasma processing chamber chemistries, and/or a plasma processing chamber flow rate input and/or output, and/or a duration of at least one plasma process. 
     
     
       16. The method of  claim 10 , wherein the RF transmission path includes at least two RF generators and each one of the at least two RF generators generate a different output signal frequency. 
     
     
       17. A plasma processing system comprising:
 a plasma processing chamber including an electrostatic chuck; 
 an RF transmission path including: 
 at least one RF generator; 
 a match circuit having an input coupled to an output of the at least one RF generator; and 
 an RF feed coupling a match circuit output to an RF input to an electrostatic chuck input; 
 an RF return path coupled between the plasma processing chamber and the at least one RF generator; and 
 a plasma processing system controller coupled to the plasma processing chamber and the RF transmission path, the plasma processing system controller including:
 a recipe logic including computer readable instructions for at least one plasma processing recipe including a plurality of plasma processing settings; and 
 an RF power compensation logic including:
 computer readable instructions for adjusting at least one of the plurality of plasma processing settings; 
 computer readable instructions for measuring a plasma induced voltage on a wafer during a calibration plasma process; and 
 computer readable instructions for comparing the plasma induced voltage measured on the wafer to a corresponding plasma induced voltage on the wafer as predicted by a complete RF transmission line model, the complete RF transmission line model including RF models for the RF transmission path, a plasma produced in the plasma processing chamber and the RF return path. 
 
 
 
     
     
       18. The system of  claim 17 , wherein the at least one RF generator includes at least two RF generators and each one of the at least two RF generators generate a different output signal frequency.